package com.da.javatest.leetCode;

/**
 * @author chenlida
 * @date 2018/12/17 15:14
 * @description
 */
public class Code617 {

    public TreeNode mergeTrees(TreeNode t1, TreeNode t2) {
        if (t1 == null && t2 == null) { return null; }
        if (t1 == null) {
            return t2;
        }
        if (t2 == null) {
            return t1;
        }
        t1.val += t2.val;
        t1.left = mergeTrees(t1.left, t2.left);
        t1.right = mergeTrees(t1.right, t2.right);
        return t1;
    }

}
